This invention relates to the preparation of cyanoalkylphenols. More specifically, this invention pertains to a process for reacting cyanide ion with p-alkenylphenols to produce the corresponding cyanoalkylphenols.
The cyanoalkylphenols produced by the process of the present invention have numerous applications and are particularly useful as chemical intermediates in the preparation of polyurethane epoxy resins and pharmaceutical and agricultural products.
The preparation of certain cyanoalkyl compounds can be accomplished by the addition of hydrogen cyanide or cyanide ion to multiple bonds (hydrocyanation). Although simple alkenes are inert towards hydrocyanation, the reaction is promoted by both electron-donating and electron-withdrawing substituents. See I. O. Sutherland, "Nitrogen Compounds, Carboxylic Acids, Phosphorus Compounds", Vol. 2 of the series Comprehensive Organic Chemistry, ed. Sir D. Barton, F.R.S., W. D. Ollis, F.R.S., Pergamon Press, New York, 1978. Heretofore, the direct hydrocyanation of alkenylphenols has not been accomplished due to inertness, oligomerization, or other side reactions.
A process for the preparation of cyanoalkylphenols involves a complex multi-step synthesis whereby a dimethylbenzylhalide is converted to the cyanide, ring nitrated, hydrogenated, and then subjected to diazotization. See A. Johnsson, Acta. Chem. Scand., 8, 1203-10 (1954). The problem with this process is that it is a low-yielding, multi-step, time-consuming, and uneconomical route.
A process for the preparation of cyanoalkylphenols is needed that would avoid hydrolysis, isomer formation, and oligomerization.